qom/object.c

   1 /*
   2  * QEMU Object Model
   3  *
   4  * Copyright IBM, Corp. 2011
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10  * See the COPYING file in the top-level directory.
  11  */
  12
  13 #include "qom/object.h"
  14 #include "qemu-common.h"
  15 #include "qapi/visitor.h"
  16 #include "qapi/string-input-visitor.h"
  17 #include "qapi/string-output-visitor.h"
  18 #include "qapi/qmp/qerror.h"
  19
  20 /* TODO: replace QObject with a simpler visitor to avoid a dependency
  21  * of the QOM core on QObject?  */
  22 #include "qom/qom-qobject.h"
  23 #include "qapi/qmp/qobject.h"
  24 #include "qapi/qmp/qbool.h"
  25 #include "qapi/qmp/qint.h"
  26 #include "qapi/qmp/qstring.h"
  27
  28 #define MAX_INTERFACES 32
  29
  30 typedef struct InterfaceImpl InterfaceImpl;
  31 typedef struct TypeImpl TypeImpl;
  32
  33 struct InterfaceImpl
  34 {
  35     const char *typename;
  36 };
  37
  38 struct TypeImpl
  39 {
  40     const char *name;
  41
  42     size_t class_size;
  43
  44     size_t instance_size;
  45
  46     void (*class_init)(ObjectClass *klass, void *data);
  47     void (*class_base_init)(ObjectClass *klass, void *data);
  48     void (*class_finalize)(ObjectClass *klass, void *data);
  49
  50     void *class_data;
  51
  52     void (*instance_init)(Object *obj);
  53     void (*instance_finalize)(Object *obj);
  54
  55     bool abstract;
  56
  57     const char *parent;
  58     TypeImpl *parent_type;
  59
  60     ObjectClass *class;
  61
  62     int num_interfaces;
  63     InterfaceImpl interfaces[MAX_INTERFACES];
  64 };
  65
  66 static Type type_interface;
  67
  68 static GHashTable *type_table_get(void)
  69 {
  70     static GHashTable *type_table;
  71
  72     if (type_table == NULL) {
  73         type_table = g_hash_table_new(g_str_hash, g_str_equal);
  74     }
  75
  76     return type_table;
  77 }
  78
  79 static void type_table_add(TypeImpl *ti)
  80 {
  81     g_hash_table_insert(type_table_get(), (void *)ti->name, ti);
  82 }
  83
  84 static TypeImpl *type_table_lookup(const char *name)
  85 {
  86     return g_hash_table_lookup(type_table_get(), name);
  87 }
  88
  89 static TypeImpl *type_register_internal(const TypeInfo *info)
  90 {
  91     TypeImpl *ti = g_malloc0(sizeof(*ti));
  92     int i;
  93
  94     g_assert(info->name != NULL);
  95
  96     if (type_table_lookup(info->name) != NULL) {
  97         fprintf(stderr, "Registering `%s' which already exists\n", info->name);
  98         abort();
  99     }
 100
 101     ti->name = g_strdup(info->name);
 102     ti->parent = g_strdup(info->parent);
 103
 104     ti->class_size = info->class_size;
 105     ti->instance_size = info->instance_size;
 106
 107     ti->class_init = info->class_init;
 108     ti->class_base_init = info->class_base_init;
 109     ti->class_finalize = info->class_finalize;
 110     ti->class_data = info->class_data;
 111
 112     ti->instance_init = info->instance_init;
 113     ti->instance_finalize = info->instance_finalize;
 114
 115     ti->abstract = info->abstract;
 116
 117     for (i = 0; info->interfaces && info->interfaces[i].type; i++) {
 118         ti->interfaces[i].typename = g_strdup(info->interfaces[i].type);
 119     }
 120     ti->num_interfaces = i;
 121
 122     type_table_add(ti);
 123
 124     return ti;
 125 }
 126
 127 TypeImpl *type_register(const TypeInfo *info)
 128 {
 129     assert(info->parent);
 130     return type_register_internal(info);
 131 }
 132
 133 TypeImpl *type_register_static(const TypeInfo *info)
 134 {
 135     return type_register(info);
 136 }
 137
 138 static TypeImpl *type_get_by_name(const char *name)
 139 {
 140     if (name == NULL) {
 141         return NULL;
 142     }
 143
 144     return type_table_lookup(name);
 145 }
 146
 147 static TypeImpl *type_get_parent(TypeImpl *type)
 148 {
 149     if (!type->parent_type && type->parent) {
 150         type->parent_type = type_get_by_name(type->parent);
 151         g_assert(type->parent_type != NULL);
 152     }
 153
 154     return type->parent_type;
 155 }
 156
 157 static bool type_has_parent(TypeImpl *type)
 158 {
 159     return (type->parent != NULL);
 160 }
 161
 162 static size_t type_class_get_size(TypeImpl *ti)
 163 {
 164     if (ti->class_size) {
 165         return ti->class_size;
 166     }
 167
 168     if (type_has_parent(ti)) {
 169         return type_class_get_size(type_get_parent(ti));
 170     }
 171
 172     return sizeof(ObjectClass);
 173 }
 174
 175 static size_t type_object_get_size(TypeImpl *ti)
 176 {
 177     if (ti->instance_size) {
 178         return ti->instance_size;
 179     }
 180
 181     if (type_has_parent(ti)) {
 182         return type_object_get_size(type_get_parent(ti));
 183     }
 184
 185     return 0;
 186 }
 187
 188 static bool type_is_ancestor(TypeImpl *type, TypeImpl *target_type)
 189 {
 190     assert(target_type);
 191
 192     /* Check if typename is a direct ancestor of type */
 193     while (type) {
 194         if (type == target_type) {
 195             return true;
 196         }
 197
 198         type = type_get_parent(type);
 199     }
 200
 201     return false;
 202 }
 203
 204 static void type_initialize(TypeImpl *ti);
 205
 206 static void type_initialize_interface(TypeImpl *ti, const char *parent)
 207 {
 208     InterfaceClass *new_iface;
 209     TypeInfo info = { };
 210     TypeImpl *iface_impl;
 211
 212     info.parent = parent;
 213     info.name = g_strdup_printf("%s::%s", ti->name, info.parent);
 214     info.abstract = true;
 215
 216     iface_impl = type_register(&info);
 217     type_initialize(iface_impl);
 218     g_free((char *)info.name);
 219
 220     new_iface = (InterfaceClass *)iface_impl->class;
 221     new_iface->concrete_class = ti->class;
 222
 223     ti->class->interfaces = g_slist_append(ti->class->interfaces,
 224                                            iface_impl->class);
 225 }
 226
 227 static void type_initialize(TypeImpl *ti)
 228 {
 229     TypeImpl *parent;
 230
 231     if (ti->class) {
 232         return;
 233     }
 234
 235     ti->class_size = type_class_get_size(ti);
 236     ti->instance_size = type_object_get_size(ti);
 237
 238     ti->class = g_malloc0(ti->class_size);
 239
 240     parent = type_get_parent(ti);
 241     if (parent) {
 242         type_initialize(parent);
 243         GSList *e;
 244         int i;
 245
 246         g_assert(parent->class_size <= ti->class_size);
 247         memcpy(ti->class, parent->class, parent->class_size);
 248         ti->class->interfaces = NULL;
 249
 250         for (e = parent->class->interfaces; e; e = e->next) {
 251             ObjectClass *iface = e->data;
 252             type_initialize_interface(ti, object_class_get_name(iface));
 253         }
 254
 255         for (i = 0; i < ti->num_interfaces; i++) {
 256             TypeImpl *t = type_get_by_name(ti->interfaces[i].typename);
 257             for (e = ti->class->interfaces; e; e = e->next) {
 258                 TypeImpl *target_type = OBJECT_CLASS(e->data)->type;
 259
 260                 if (type_is_ancestor(target_type, t)) {
 261                     break;
 262                 }
 263             }
 264
 265             if (e) {
 266                 continue;
 267             }
 268
 269             type_initialize_interface(ti, ti->interfaces[i].typename);
 270         }
 271     }
 272
 273     ti->class->type = ti;
 274
 275     while (parent) {
 276         if (parent->class_base_init) {
 277             parent->class_base_init(ti->class, ti->class_data);
 278         }
 279         parent = type_get_parent(parent);
 280     }
 281
 282     if (ti->class_init) {
 283         ti->class_init(ti->class, ti->class_data);
 284     }
 285
 286
 287 }
 288
 289 static void object_init_with_type(Object *obj, TypeImpl *ti)
 290 {
 291     if (type_has_parent(ti)) {
 292         object_init_with_type(obj, type_get_parent(ti));
 293     }
 294
 295     if (ti->instance_init) {
 296         ti->instance_init(obj);
 297     }
 298 }
 299
 300 void object_initialize_with_type(void *data, TypeImpl *type)
 301 {
 302     Object *obj = data;
 303
 304     g_assert(type != NULL);
 305     type_initialize(type);
 306
 307     g_assert(type->instance_size >= sizeof(Object));
 308     g_assert(type->abstract == false);
 309
 310     memset(obj, 0, type->instance_size);
 311     obj->class = type->class;
 312     object_ref(obj);
 313     QTAILQ_INIT(&obj->properties);
 314     object_init_with_type(obj, type);
 315 }
 316
 317 void object_initialize(void *data, const char *typename)
 318 {
 319     TypeImpl *type = type_get_by_name(typename);
 320
 321     object_initialize_with_type(data, type);
 322 }
 323
 324 static inline bool object_property_is_child(ObjectProperty *prop)
 325 {
 326     return strstart(prop->type, "child<", NULL);
 327 }
 328
 329 static inline bool object_property_is_link(ObjectProperty *prop)
 330 {
 331     return strstart(prop->type, "link<", NULL);
 332 }
 333
 334 static void object_property_del_all(Object *obj)
 335 {
 336     while (!QTAILQ_EMPTY(&obj->properties)) {
 337         ObjectProperty *prop = QTAILQ_FIRST(&obj->properties);
 338
 339         QTAILQ_REMOVE(&obj->properties, prop, node);
 340
 341         if (prop->release) {
 342             prop->release(obj, prop->name, prop->opaque);
 343         }
 344
 345         g_free(prop->name);
 346         g_free(prop->type);
 347         g_free(prop);
 348     }
 349 }
 350
 351 static void object_property_del_child(Object *obj, Object *child, Error **errp)
 352 {
 353     ObjectProperty *prop;
 354
 355     QTAILQ_FOREACH(prop, &obj->properties, node) {
 356         if (object_property_is_child(prop) && prop->opaque == child) {
 357             object_property_del(obj, prop->name, errp);
 358             break;
 359         }
 360     }
 361 }
 362
 363 void object_unparent(Object *obj)
 364 {
 365     object_ref(obj);
 366     if (obj->class->unparent) {
 367         (obj->class->unparent)(obj);
 368     }
 369     if (obj->parent) {
 370         object_property_del_child(obj->parent, obj, NULL);
 371     }
 372     object_unref(obj);
 373 }
 374
 375 static void object_deinit(Object *obj, TypeImpl *type)
 376 {
 377     if (type->instance_finalize) {
 378         type->instance_finalize(obj);
 379     }
 380
 381     if (type_has_parent(type)) {
 382         object_deinit(obj, type_get_parent(type));
 383     }
 384 }
 385
 386 static void object_finalize(void *data)
 387 {
 388     Object *obj = data;
 389     TypeImpl *ti = obj->class->type;
 390
 391     object_deinit(obj, ti);
 392     object_property_del_all(obj);
 393
 394     g_assert(obj->ref == 0);
 395     if (obj->free) {
 396         obj->free(obj);
 397     }
 398 }
 399
 400 Object *object_new_with_type(Type type)
 401 {
 402     Object *obj;
 403
 404     g_assert(type != NULL);
 405     type_initialize(type);
 406
 407     obj = g_malloc(type->instance_size);
 408     object_initialize_with_type(obj, type);
 409     obj->free = g_free;
 410
 411     return obj;
 412 }
 413
 414 Object *object_new(const char *typename)
 415 {
 416     TypeImpl *ti = type_get_by_name(typename);
 417
 418     return object_new_with_type(ti);
 419 }
 420
 421 Object *object_dynamic_cast(Object *obj, const char *typename)
 422 {
 423     if (obj && object_class_dynamic_cast(object_get_class(obj), typename)) {
 424         return obj;
 425     }
 426
 427     return NULL;
 428 }
 429
 430 Object *object_dynamic_cast_assert(Object *obj, const char *typename)
 431 {
 432     Object *inst;
 433
 434     inst = object_dynamic_cast(obj, typename);
 435
 436     if (!inst && obj) {
 437         fprintf(stderr, "Object %p is not an instance of type %s\n",
 438                 obj, typename);
 439         abort();
 440     }
 441
 442     return inst;
 443 }
 444
 445 ObjectClass *object_class_dynamic_cast(ObjectClass *class,
 446                                        const char *typename)
 447 {
 448     TypeImpl *target_type = type_get_by_name(typename);
 449     TypeImpl *type = class->type;
 450     ObjectClass *ret = NULL;
 451
 452     if (type->class->interfaces &&
 453             type_is_ancestor(target_type, type_interface)) {
 454         int found = 0;
 455         GSList *i;
 456
 457         for (i = class->interfaces; i; i = i->next) {
 458             ObjectClass *target_class = i->data;
 459
 460             if (type_is_ancestor(target_class->type, target_type)) {
 461                 ret = target_class;
 462                 found++;
 463             }
 464          }
 465
 466         /* The match was ambiguous, don't allow a cast */
 467         if (found > 1) {
 468             ret = NULL;
 469         }
 470     } else if (type_is_ancestor(type, target_type)) {
 471         ret = class;
 472     }
 473
 474     return ret;
 475 }
 476
 477 ObjectClass *object_class_dynamic_cast_assert(ObjectClass *class,
 478                                               const char *typename)
 479 {
 480     ObjectClass *ret = object_class_dynamic_cast(class, typename);
 481
 482     if (!ret) {
 483         fprintf(stderr, "Object %p is not an instance of type %s\n",
 484                 class, typename);
 485         abort();
 486     }
 487
 488     return ret;
 489 }
 490
 491 const char *object_get_typename(Object *obj)
 492 {
 493     return obj->class->type->name;
 494 }
 495
 496 ObjectClass *object_get_class(Object *obj)
 497 {
 498     return obj->class;
 499 }
 500
 501 bool object_class_is_abstract(ObjectClass *klass)
 502 {
 503     return klass->type->abstract;
 504 }
 505
 506 const char *object_class_get_name(ObjectClass *klass)
 507 {
 508     return klass->type->name;
 509 }
 510
 511 ObjectClass *object_class_by_name(const char *typename)
 512 {
 513     TypeImpl *type = type_get_by_name(typename);
 514
 515     if (!type) {
 516         return NULL;
 517     }
 518
 519     type_initialize(type);
 520
 521     return type->class;
 522 }
 523
 524 ObjectClass *object_class_get_parent(ObjectClass *class)
 525 {
 526     TypeImpl *type = type_get_parent(class->type);
 527
 528     if (!type) {
 529         return NULL;
 530     }
 531
 532     type_initialize(type);
 533
 534     return type->class;
 535 }
 536
 537 typedef struct OCFData
 538 {
 539     void (*fn)(ObjectClass *klass, void *opaque);
 540     const char *implements_type;
 541     bool include_abstract;
 542     void *opaque;
 543 } OCFData;
 544
 545 static void object_class_foreach_tramp(gpointer key, gpointer value,
 546                                        gpointer opaque)
 547 {
 548     OCFData *data = opaque;
 549     TypeImpl *type = value;
 550     ObjectClass *k;
 551
 552     type_initialize(type);
 553     k = type->class;
 554
 555     if (!data->include_abstract && type->abstract) {
 556         return;
 557     }
 558
 559     if (data->implements_type &&
 560         !object_class_dynamic_cast(k, data->implements_type)) {
 561         return;
 562     }
 563
 564     data->fn(k, data->opaque);
 565 }
 566
 567 void object_class_foreach(void (*fn)(ObjectClass *klass, void *opaque),
 568                           const char *implements_type, bool include_abstract,
 569                           void *opaque)
 570 {
 571     OCFData data = { fn, implements_type, include_abstract, opaque };
 572
 573     g_hash_table_foreach(type_table_get(), object_class_foreach_tramp, &data);
 574 }
 575
 576 int object_child_foreach(Object *obj, int (*fn)(Object *child, void *opaque),
 577                          void *opaque)
 578 {
 579     ObjectProperty *prop;
 580     int ret = 0;
 581
 582     QTAILQ_FOREACH(prop, &obj->properties, node) {
 583         if (object_property_is_child(prop)) {
 584             ret = fn(prop->opaque, opaque);
 585             if (ret != 0) {
 586                 break;
 587             }
 588         }
 589     }
 590     return ret;
 591 }
 592
 593 static void object_class_get_list_tramp(ObjectClass *klass, void *opaque)
 594 {
 595     GSList **list = opaque;
 596
 597     *list = g_slist_prepend(*list, klass);
 598 }
 599
 600 GSList *object_class_get_list(const char *implements_type,
 601                               bool include_abstract)
 602 {
 603     GSList *list = NULL;
 604
 605     object_class_foreach(object_class_get_list_tramp,
 606                          implements_type, include_abstract, &list);
 607     return list;
 608 }
 609
 610 void object_ref(Object *obj)
 611 {
 612     obj->ref++;
 613 }
 614
 615 void object_unref(Object *obj)
 616 {
 617     g_assert(obj->ref > 0);
 618     obj->ref--;
 619
 620     /* parent always holds a reference to its children */
 621     if (obj->ref == 0) {
 622         object_finalize(obj);
 623     }
 624 }
 625
 626 void object_property_add(Object *obj, const char *name, const char *type,
 627                          ObjectPropertyAccessor *get,
 628                          ObjectPropertyAccessor *set,
 629                          ObjectPropertyRelease *release,
 630                          void *opaque, Error **errp)
 631 {
 632     ObjectProperty *prop;
 633
 634     QTAILQ_FOREACH(prop, &obj->properties, node) {
 635         if (strcmp(prop->name, name) == 0) {
 636             error_setg(errp, "attempt to add duplicate property '%s'"
 637                        " to object (type '%s')", name,
 638                        object_get_typename(obj));
 639             return;
 640         }
 641     }
 642
 643     prop = g_malloc0(sizeof(*prop));
 644
 645     prop->name = g_strdup(name);
 646     prop->type = g_strdup(type);
 647
 648     prop->get = get;
 649     prop->set = set;
 650     prop->release = release;
 651     prop->opaque = opaque;
 652
 653     QTAILQ_INSERT_TAIL(&obj->properties, prop, node);
 654 }
 655
 656 ObjectProperty *object_property_find(Object *obj, const char *name,
 657                                      Error **errp)
 658 {
 659     ObjectProperty *prop;
 660
 661     QTAILQ_FOREACH(prop, &obj->properties, node) {
 662         if (strcmp(prop->name, name) == 0) {
 663             return prop;
 664         }
 665     }
 666
 667     error_set(errp, QERR_PROPERTY_NOT_FOUND, "", name);
 668     return NULL;
 669 }
 670
 671 void object_property_del(Object *obj, const char *name, Error **errp)
 672 {
 673     ObjectProperty *prop = object_property_find(obj, name, errp);
 674     if (prop == NULL) {
 675         return;
 676     }
 677
 678     if (prop->release) {
 679         prop->release(obj, name, prop->opaque);
 680     }
 681
 682     QTAILQ_REMOVE(&obj->properties, prop, node);
 683
 684     g_free(prop->name);
 685     g_free(prop->type);
 686     g_free(prop);
 687 }
 688
 689 void object_property_get(Object *obj, Visitor *v, const char *name,
 690                          Error **errp)
 691 {
 692     ObjectProperty *prop = object_property_find(obj, name, errp);
 693     if (prop == NULL) {
 694         return;
 695     }
 696
 697     if (!prop->get) {
 698         error_set(errp, QERR_PERMISSION_DENIED);
 699     } else {
 700         prop->get(obj, v, prop->opaque, name, errp);
 701     }
 702 }
 703
 704 void object_property_set(Object *obj, Visitor *v, const char *name,
 705                          Error **errp)
 706 {
 707     ObjectProperty *prop = object_property_find(obj, name, errp);
 708     if (prop == NULL) {
 709         return;
 710     }
 711
 712     if (!prop->set) {
 713         error_set(errp, QERR_PERMISSION_DENIED);
 714     } else {
 715         prop->set(obj, v, prop->opaque, name, errp);
 716     }
 717 }
 718
 719 void object_property_set_str(Object *obj, const char *value,
 720                              const char *name, Error **errp)
 721 {
 722     QString *qstr = qstring_from_str(value);
 723     object_property_set_qobject(obj, QOBJECT(qstr), name, errp);
 724
 725     QDECREF(qstr);
 726 }
 727
 728 char *object_property_get_str(Object *obj, const char *name,
 729                               Error **errp)
 730 {
 731     QObject *ret = object_property_get_qobject(obj, name, errp);
 732     QString *qstring;
 733     char *retval;
 734
 735     if (!ret) {
 736         return NULL;
 737     }
 738     qstring = qobject_to_qstring(ret);
 739     if (!qstring) {
 740         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "string");
 741         retval = NULL;
 742     } else {
 743         retval = g_strdup(qstring_get_str(qstring));
 744     }
 745
 746     QDECREF(qstring);
 747     return retval;
 748 }
 749
 750 void object_property_set_link(Object *obj, Object *value,
 751                               const char *name, Error **errp)
 752 {
 753     object_property_set_str(obj, object_get_canonical_path(value),
 754                             name, errp);
 755 }
 756
 757 Object *object_property_get_link(Object *obj, const char *name,
 758                                  Error **errp)
 759 {
 760     char *str = object_property_get_str(obj, name, errp);
 761     Object *target = NULL;
 762
 763     if (str && *str) {
 764         target = object_resolve_path(str, NULL);
 765         if (!target) {
 766             error_set(errp, QERR_DEVICE_NOT_FOUND, str);
 767         }
 768     }
 769
 770     g_free(str);
 771     return target;
 772 }
 773
 774 void object_property_set_bool(Object *obj, bool value,
 775                               const char *name, Error **errp)
 776 {
 777     QBool *qbool = qbool_from_int(value);
 778     object_property_set_qobject(obj, QOBJECT(qbool), name, errp);
 779
 780     QDECREF(qbool);
 781 }
 782
 783 bool object_property_get_bool(Object *obj, const char *name,
 784                               Error **errp)
 785 {
 786     QObject *ret = object_property_get_qobject(obj, name, errp);
 787     QBool *qbool;
 788     bool retval;
 789
 790     if (!ret) {
 791         return false;
 792     }
 793     qbool = qobject_to_qbool(ret);
 794     if (!qbool) {
 795         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "boolean");
 796         retval = false;
 797     } else {
 798         retval = qbool_get_int(qbool);
 799     }
 800
 801     QDECREF(qbool);
 802     return retval;
 803 }
 804
 805 void object_property_set_int(Object *obj, int64_t value,
 806                              const char *name, Error **errp)
 807 {
 808     QInt *qint = qint_from_int(value);
 809     object_property_set_qobject(obj, QOBJECT(qint), name, errp);
 810
 811     QDECREF(qint);
 812 }
 813
 814 int64_t object_property_get_int(Object *obj, const char *name,
 815                                 Error **errp)
 816 {
 817     QObject *ret = object_property_get_qobject(obj, name, errp);
 818     QInt *qint;
 819     int64_t retval;
 820
 821     if (!ret) {
 822         return -1;
 823     }
 824     qint = qobject_to_qint(ret);
 825     if (!qint) {
 826         error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, "int");
 827         retval = -1;
 828     } else {
 829         retval = qint_get_int(qint);
 830     }
 831
 832     QDECREF(qint);
 833     return retval;
 834 }
 835
 836 void object_property_parse(Object *obj, const char *string,
 837                            const char *name, Error **errp)
 838 {
 839     StringInputVisitor *mi;
 840     mi = string_input_visitor_new(string);
 841     object_property_set(obj, string_input_get_visitor(mi), name, errp);
 842
 843     string_input_visitor_cleanup(mi);
 844 }
 845
 846 char *object_property_print(Object *obj, const char *name,
 847                             Error **errp)
 848 {
 849     StringOutputVisitor *mo;
 850     char *string;
 851
 852     mo = string_output_visitor_new();
 853     object_property_get(obj, string_output_get_visitor(mo), name, errp);
 854     string = string_output_get_string(mo);
 855     string_output_visitor_cleanup(mo);
 856     return string;
 857 }
 858
 859 const char *object_property_get_type(Object *obj, const char *name, Error **errp)
 860 {
 861     ObjectProperty *prop = object_property_find(obj, name, errp);
 862     if (prop == NULL) {
 863         return NULL;
 864     }
 865
 866     return prop->type;
 867 }
 868
 869 Object *object_get_root(void)
 870 {
 871     static Object *root;
 872
 873     if (!root) {
 874         root = object_new("container");
 875     }
 876
 877     return root;
 878 }
 879
 880 static void object_get_child_property(Object *obj, Visitor *v, void *opaque,
 881                                       const char *name, Error **errp)
 882 {
 883     Object *child = opaque;
 884     gchar *path;
 885
 886     path = object_get_canonical_path(child);
 887     visit_type_str(v, &path, name, errp);
 888     g_free(path);
 889 }
 890
 891 static void object_finalize_child_property(Object *obj, const char *name,
 892                                            void *opaque)
 893 {
 894     Object *child = opaque;
 895
 896     object_unref(child);
 897 }
 898
 899 void object_property_add_child(Object *obj, const char *name,
 900                                Object *child, Error **errp)
 901 {
 902     gchar *type;
 903
 904     type = g_strdup_printf("child<%s>", object_get_typename(OBJECT(child)));
 905
 906     object_property_add(obj, name, type, object_get_child_property,
 907                         NULL, object_finalize_child_property, child, errp);
 908
 909     object_ref(child);
 910     g_assert(child->parent == NULL);
 911     child->parent = obj;
 912
 913     g_free(type);
 914 }
 915
 916 static void object_get_link_property(Object *obj, Visitor *v, void *opaque,
 917                                      const char *name, Error **errp)
 918 {
 919     Object **child = opaque;
 920     gchar *path;
 921
 922     if (*child) {
 923         path = object_get_canonical_path(*child);
 924         visit_type_str(v, &path, name, errp);
 925         g_free(path);
 926     } else {
 927         path = (gchar *)"";
 928         visit_type_str(v, &path, name, errp);
 929     }
 930 }
 931
 932 static void object_set_link_property(Object *obj, Visitor *v, void *opaque,
 933                                      const char *name, Error **errp)
 934 {
 935     Object **child = opaque;
 936     Object *old_target;
 937     bool ambiguous = false;
 938     const char *type;
 939     char *path;
 940     gchar *target_type;
 941
 942     type = object_property_get_type(obj, name, NULL);
 943
 944     visit_type_str(v, &path, name, errp);
 945
 946     old_target = *child;
 947     *child = NULL;
 948
 949     if (strcmp(path, "") != 0) {
 950         Object *target;
 951
 952         /* Go from link<FOO> to FOO.  */
 953         target_type = g_strndup(&type[5], strlen(type) - 6);
 954         target = object_resolve_path_type(path, target_type, &ambiguous);
 955
 956         if (ambiguous) {
 957             error_set(errp, QERR_AMBIGUOUS_PATH, path);
 958         } else if (target) {
 959             object_ref(target);
 960             *child = target;
 961         } else {
 962             target = object_resolve_path(path, &ambiguous);
 963             if (target || ambiguous) {
 964                 error_set(errp, QERR_INVALID_PARAMETER_TYPE, name, target_type);
 965             } else {
 966                 error_set(errp, QERR_DEVICE_NOT_FOUND, path);
 967             }
 968         }
 969         g_free(target_type);
 970     }
 971
 972     g_free(path);
 973
 974     if (old_target != NULL) {
 975         object_unref(old_target);
 976     }
 977 }
 978
 979 void object_property_add_link(Object *obj, const char *name,
 980                               const char *type, Object **child,
 981                               Error **errp)
 982 {
 983     gchar *full_type;
 984
 985     full_type = g_strdup_printf("link<%s>", type);
 986
 987     object_property_add(obj, name, full_type,
 988                         object_get_link_property,
 989                         object_set_link_property,
 990                         NULL, child, errp);
 991
 992     g_free(full_type);
 993 }
 994
 995 gchar *object_get_canonical_path(Object *obj)
 996 {
 997     Object *root = object_get_root();
 998     char *newpath = NULL, *path = NULL;
 999
1000     while (obj != root) {
1001         ObjectProperty *prop = NULL;
1002
1003         g_assert(obj->parent != NULL);
1004
1005         QTAILQ_FOREACH(prop, &obj->parent->properties, node) {
1006             if (!object_property_is_child(prop)) {
1007                 continue;
1008             }
1009
1010             if (prop->opaque == obj) {
1011                 if (path) {
1012                     newpath = g_strdup_printf("%s/%s", prop->name, path);
1013                     g_free(path);
1014                     path = newpath;
1015                 } else {
1016                     path = g_strdup(prop->name);
1017                 }
1018                 break;
1019             }
1020         }
1021
1022         g_assert(prop != NULL);
1023
1024         obj = obj->parent;
1025     }
1026
1027     newpath = g_strdup_printf("/%s", path);
1028     g_free(path);
1029
1030     return newpath;
1031 }
1032
1033 Object *object_resolve_path_component(Object *parent, const gchar *part)
1034 {
1035     ObjectProperty *prop = object_property_find(parent, part, NULL);
1036     if (prop == NULL) {
1037         return NULL;
1038     }
1039
1040     if (object_property_is_link(prop)) {
1041         return *(Object **)prop->opaque;
1042     } else if (object_property_is_child(prop)) {
1043         return prop->opaque;
1044     } else {
1045         return NULL;
1046     }
1047 }
1048
1049 static Object *object_resolve_abs_path(Object *parent,
1050                                           gchar **parts,
1051                                           const char *typename,
1052                                           int index)
1053 {
1054     Object *child;
1055
1056     if (parts[index] == NULL) {
1057         return object_dynamic_cast(parent, typename);
1058     }
1059
1060     if (strcmp(parts[index], "") == 0) {
1061         return object_resolve_abs_path(parent, parts, typename, index + 1);
1062     }
1063
1064     child = object_resolve_path_component(parent, parts[index]);
1065     if (!child) {
1066         return NULL;
1067     }
1068
1069     return object_resolve_abs_path(child, parts, typename, index + 1);
1070 }
1071
1072 static Object *object_resolve_partial_path(Object *parent,
1073                                               gchar **parts,
1074                                               const char *typename,
1075                                               bool *ambiguous)
1076 {
1077     Object *obj;
1078     ObjectProperty *prop;
1079
1080     obj = object_resolve_abs_path(parent, parts, typename, 0);
1081
1082     QTAILQ_FOREACH(prop, &parent->properties, node) {
1083         Object *found;
1084
1085         if (!object_property_is_child(prop)) {
1086             continue;
1087         }
1088
1089         found = object_resolve_partial_path(prop->opaque, parts,
1090                                             typename, ambiguous);
1091         if (found) {
1092             if (obj) {
1093                 if (ambiguous) {
1094                     *ambiguous = true;
1095                 }
1096                 return NULL;
1097             }
1098             obj = found;
1099         }
1100
1101         if (ambiguous && *ambiguous) {
1102             return NULL;
1103         }
1104     }
1105
1106     return obj;
1107 }
1108
1109 Object *object_resolve_path_type(const char *path, const char *typename,
1110                                  bool *ambiguous)
1111 {
1112     bool partial_path = true;
1113     Object *obj;
1114     gchar **parts;
1115
1116     parts = g_strsplit(path, "/", 0);
1117     if (parts == NULL || parts[0] == NULL) {
1118         g_strfreev(parts);
1119         return object_get_root();
1120     }
1121
1122     if (strcmp(parts[0], "") == 0) {
1123         partial_path = false;
1124     }
1125
1126     if (partial_path) {
1127         if (ambiguous) {
1128             *ambiguous = false;
1129         }
1130         obj = object_resolve_partial_path(object_get_root(), parts,
1131                                           typename, ambiguous);
1132     } else {
1133         obj = object_resolve_abs_path(object_get_root(), parts, typename, 1);
1134     }
1135
1136     g_strfreev(parts);
1137
1138     return obj;
1139 }
1140
1141 Object *object_resolve_path(const char *path, bool *ambiguous)
1142 {
1143     return object_resolve_path_type(path, TYPE_OBJECT, ambiguous);
1144 }
1145
1146 typedef struct StringProperty
1147 {
1148     char *(*get)(Object *, Error **);
1149     void (*set)(Object *, const char *, Error **);
1150 } StringProperty;
1151
1152 static void property_get_str(Object *obj, Visitor *v, void *opaque,
1153                              const char *name, Error **errp)
1154 {
1155     StringProperty *prop = opaque;
1156     char *value;
1157
1158     value = prop->get(obj, errp);
1159     if (value) {
1160         visit_type_str(v, &value, name, errp);
1161         g_free(value);
1162     }
1163 }
1164
1165 static void property_set_str(Object *obj, Visitor *v, void *opaque,
1166                              const char *name, Error **errp)
1167 {
1168     StringProperty *prop = opaque;
1169     char *value;
1170     Error *local_err = NULL;
1171
1172     visit_type_str(v, &value, name, &local_err);
1173     if (local_err) {
1174         error_propagate(errp, local_err);
1175         return;
1176     }
1177
1178     prop->set(obj, value, errp);
1179     g_free(value);
1180 }
1181
1182 static void property_release_str(Object *obj, const char *name,
1183                                  void *opaque)
1184 {
1185     StringProperty *prop = opaque;
1186     g_free(prop);
1187 }
1188
1189 void object_property_add_str(Object *obj, const char *name,
1190                            char *(*get)(Object *, Error **),
1191                            void (*set)(Object *, const char *, Error **),
1192                            Error **errp)
1193 {
1194     StringProperty *prop = g_malloc0(sizeof(*prop));
1195
1196     prop->get = get;
1197     prop->set = set;
1198
1199     object_property_add(obj, name, "string",
1200                         get ? property_get_str : NULL,
1201                         set ? property_set_str : NULL,
1202                         property_release_str,
1203                         prop, errp);
1204 }
1205
1206 typedef struct BoolProperty
1207 {
1208     bool (*get)(Object *, Error **);
1209     void (*set)(Object *, bool, Error **);
1210 } BoolProperty;
1211
1212 static void property_get_bool(Object *obj, Visitor *v, void *opaque,
1213                               const char *name, Error **errp)
1214 {
1215     BoolProperty *prop = opaque;
1216     bool value;
1217
1218     value = prop->get(obj, errp);
1219     visit_type_bool(v, &value, name, errp);
1220 }
1221
1222 static void property_set_bool(Object *obj, Visitor *v, void *opaque,
1223                               const char *name, Error **errp)
1224 {
1225     BoolProperty *prop = opaque;
1226     bool value;
1227     Error *local_err = NULL;
1228
1229     visit_type_bool(v, &value, name, &local_err);
1230     if (local_err) {
1231         error_propagate(errp, local_err);
1232         return;
1233     }
1234
1235     prop->set(obj, value, errp);
1236 }
1237
1238 static void property_release_bool(Object *obj, const char *name,
1239                                   void *opaque)
1240 {
1241     BoolProperty *prop = opaque;
1242     g_free(prop);
1243 }
1244
1245 void object_property_add_bool(Object *obj, const char *name,
1246                               bool (*get)(Object *, Error **),
1247                               void (*set)(Object *, bool, Error **),
1248                               Error **errp)
1249 {
1250     BoolProperty *prop = g_malloc0(sizeof(*prop));
1251
1252     prop->get = get;
1253     prop->set = set;
1254
1255     object_property_add(obj, name, "bool",
1256                         get ? property_get_bool : NULL,
1257                         set ? property_set_bool : NULL,
1258                         property_release_bool,
1259                         prop, errp);
1260 }
1261
1262 static char *qdev_get_type(Object *obj, Error **errp)
1263 {
1264     return g_strdup(object_get_typename(obj));
1265 }
1266
1267 static void object_instance_init(Object *obj)
1268 {
1269     object_property_add_str(obj, "type", qdev_get_type, NULL, NULL);
1270 }
1271
1272 static void register_types(void)
1273 {
1274     static TypeInfo interface_info = {
1275         .name = TYPE_INTERFACE,
1276         .class_size = sizeof(InterfaceClass),
1277         .abstract = true,
1278     };
1279
1280     static TypeInfo object_info = {
1281         .name = TYPE_OBJECT,
1282         .instance_size = sizeof(Object),
1283         .instance_init = object_instance_init,
1284         .abstract = true,
1285     };
1286
1287     type_interface = type_register_internal(&interface_info);
1288     type_register_internal(&object_info);
1289 }
1290
1291 type_init(register_types)